What is the term for the light emitted by certain materials when struck by ionizing radiation?

What is the term for the light emitted by certain materials when struck by ionizing radiation?

• A. Scintillation
• B. Phosphorescence
• C. Luminescence
• D. Fluorescence

Answer: (A)

Light emitted by certain materials when struck by ionizing radiation is called scintillation. In a scintillator, the incoming radiation deposits energy that excites the material’s atoms; as these excited states return to their ground state, photons are released in a very short time, typically nanoseconds to microseconds. The light yield often scales with the energy deposited, which is why scintillators are used to detect and measure radiation. Phosphorescence involves a delayed afterglow caused by traps in the material, lasting longer after excitation. Luminescence is the broad umbrella term for light emission from a material after excitation, and fluorescence is a fast emission of light following excitation but is not specific to the rapid, detector-focused light produced by ionizing radiation in scintillators.

Light emitted by certain materials when struck by ionizing radiation is called scintillation. In a scintillator, the incoming radiation deposits energy that excites the material’s atoms; as these excited states return to their ground state, photons are released in a very short time, typically nanoseconds to microseconds. The light yield often scales with the energy deposited, which is why scintillators are used to detect and measure radiation.

Phosphorescence involves a delayed afterglow caused by traps in the material, lasting longer after excitation. Luminescence is the broad umbrella term for light emission from a material after excitation, and fluorescence is a fast emission of light following excitation but is not specific to the rapid, detector-focused light produced by ionizing radiation in scintillators.